<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
</head>
<script>
	var a=new String("i am szj. hah aha 233");
	var b=new String("ta shi  he re ter");
	console.log(a.charAt(3));
	console.log(a.length);
	console.log(b.length);
	console.log(a.indexOf("a"));
	console.log(a.substring(5,9));
	console.log(a.substring(5));
	console.log(a.substr(5,9));
	console.log(a.toLowerCase());
	console.log(a.toLocaleUpperCase());
	console.log(a.split(""));
	console.log(a.replace("18","eighteen"));
	console.log(b.concat("x","y","z"));//衔接
	console.log(a.trim());//去除空格
	</script>

<body>
</body>
</html>
